1. Field of the Invention
This invention relates to a composition for external application, for example, a skin and hair cosmetic composition and a external medical composition, and more particularly, to a composition for external application exhibiting an excellent moisture-retention effect and imparting moistened feel without sliminess and irritation to the skin.
2. Description of the Background Art
A proper amount of water generally contained in the outermost crust of the skin and hair is indispensable for maintaining flexibility, softness, protective functions of the skin and hair. When the water content in the skin decreases, for example, the skin turns into, namely, dry skin, in which its flexibility and protective function are lost, resulting in a cause of various troubles. Whereas, sebum is known to have an important function to prevent the excessive loss of water from the outermost crust of the skin and hair and consequently can avoid the above-mentioned troubles.
In this regard, various oils including squalane which is a component involved in the skin, have conventionally been used as a component for cosmetics and the like to prevent the skin and hair from excessive drying.
However, external compositions containing these oils, e.g. cosmetics and the like, have disadvantages that they generally exhibit high sliminess when applied and give unacceptable feel upon use. On the other hand, hydrocarbons of low melting points are known as a less slimy oil component, however, they inevitably impart irritation to the skin under closed conditions.
Compositions for external application exhibiting an excellent moisture-retention effect without sliminess and irritation to the skin have therefore been desired.
In view of this situation, the present inventors have undertaken extensive studies to solve the above-mentioned problems. As a result, the inventors have found that a composition for external application comprising a specific tricyclic saturated hydrocarbon could exhibit an excellent moisture-retention effect, impart moistened feel, and have high safety without sliminess and irritation to the skin. This finding has led to the completion of the invention.